Answer:

Step-by-step explanation:
we know that
In the diagram


Equate


4x + 7x = 33
11x = 33
x = 3
4x = 4(3) = 12
7x = 7(3) = 21
12 and 21 are how you split 33 in to a ratio of 4 to 7.
Answer:
6 red balls
Step-by-step explanation:
The probability in the first pick
6/21
The probability in the second pick (without replacement)
5/20
the requested probability
(6/21)(5/20) = 30/420
simplification
30/420 = 3/42 = 1/14
Hope this helps